Mario Lucertini

Scheduling of flexible flow lines in an automobile assembly plant

This paper deals with the material flow management in a large-scale manufacturing process, namely the assembly of automobiles in a highly automated plant in Italy. After a detailed description of the plant from the viewpoint of material flow issues, the modeling process and the methodologies employed to address the problems are illustrated. The decision models were validated by means of simulations of the real plant in several different production scenarios (varying demand volume and mix, resource availability etc.).

Most uniform path partitioning and its use in image processing

Abstract Let Q be a vertex-weighted path with n vertices. For any pair (L,U) can one find a partition of Q into (a given number p of) subpaths, such that the total weight of every subpath lies between L and U? We present linear-time algorithms for the partitioning problem for given (L,U) and an O(n 2 p log n ) algorithm, relying on the above procedures, for finding a partition that minimizes the difference between the largest and the smallest weight of a subpath (most uniform partitioning). Our approach combines a preprocessing procedure, which detects “obstructions”, if any, via a sequence of vertex compressions; and a greedy procedure, which actually finds the desired partition. Path partitioning can be a useful tool in facing image degradation. In fact whenever a picture is taken or converted from one form to another, the resulting image can be affected by different types and degrees of degradation; if we have no informations on the actual degradation process that has taken place on the image (or if it is too difficult or costly to find such informations), the only way for image enhancement consists in increasing contrast and reducing noise by suitable modifications of the grey level of pixels. Finding the optimal grey scale transformation which leads to this enhancement can be formulated as the problem of partitioning into connected components a path with vertices corresponding to grey levels and vertex weights equal to the number of occurrences of the corresponding tone in the image, so that the sum of the weights of the vertices in each component is “as constant as possible”. In addition to image processing, this problem has applications in paging, clustering and the design of communication networks.

Fair dissections of spiders, worms, and caterpillars

In the present paper we deal with equipartition problems for special classes of trees, i. e., spiders, stars, worms, and caterpillars. We prove that the equipartition problem is NP-complete for spiders (and, hence, for general trees); on the other hand, we give efficient polynomial-time algorithms for stars, worms, and caterpillars.

Max‐min partitioning of grid graphs into connected components

The partitioning of a rectangular grid graph with weighted vertices into p connected components such that the component of smallest weight is as heavy as possible (the max-min problem) is considered. It is shown that the problem is NP-hard for rectangles with at least three rows. A shifting algorithm is given which approximates the optimal solution. Bounds for the relative error are determined under a posteriori hypotheses. A further shifting algorithm is also given which allows for error estimates under a priori hypotheses and for asymptotic error estimates. A similar approach can be taken with the problem of finding the partition whose largest component is as small as possible (the min-max problem). The case of rectangles with two rows has a polynomial algorithm and is dealt with in another paper.

Technological Concepts and Mathematical Models in the Evolution of Modern Engineering Systems

Download PDF Ebook and Read OnlineTechnological Concepts And Mathematical Models In The Evolution Of Modern Engineering Systems. Get Technological Concepts And Mathematical Models In The Evolution Of Modern Engineering Systems Presents currently this technological concepts and mathematical models in the evolution of modern engineering systems as one of your book collection! But, it is not in your bookcase compilations. Why? This is the book technological concepts and mathematical models in the evolution of modern engineering systems that is offered in soft documents. You can download and install the soft data of this magnificent book technological concepts and mathematical models in the evolution of modern engineering systems now and in the web link supplied. Yeah, different with the other individuals who look for book technological concepts and mathematical models in the evolution of modern engineering systems outside, you can obtain much easier to present this book. When some people still stroll right into the establishment as well as look guide technological concepts and mathematical models in the evolution of modern engineering systems, you are right here just stay on your seat and obtain the book technological concepts and mathematical models in the evolution of modern engineering systems. When you are hurried of job target date and have no concept to obtain inspiration, technological concepts and mathematical models in the evolution of modern engineering systems publication is one of your remedies to take. Reserve technological concepts and mathematical models in the evolution of modern engineering systems will give you the ideal resource as well as point to obtain motivations. It is not only concerning the tasks for politic business, management, economics, and various other. Some got jobs making some fiction your jobs likewise require motivations to get over the job. As what you need, this technological concepts and mathematical models in the evolution of modern engineering systems will probably be your option. While the other individuals in the store, they are not exactly sure to locate this technological concepts and mathematical models in the evolution of modern engineering systems directly. It might need more times to go shop by shop. This is why we intend you this website. We will certainly supply the most effective way and reference to obtain guide technological concepts and mathematical models in the evolution of modern engineering systems Even this is soft file book, it will certainly be ease to bring technological concepts and

Integrating Layout Design and Material Flow Management in Assembly Systems

The material flow management of flexible assembly systems requires to assign a set of operations to a set of machines, and to connect machines by a transportation network, such that a number of constraints is satisfied and some efficiency index is optimized Aim of the paper is to give a general framework to formulate and model, in a formal way, different subproblems arising from embedding an assembly process on different configurations of a flexible production system. We analyze several wide used architectures and material flow policies, and point out some useful properties to design decision rules and evaluate the corresponding optimality bounds. The paper also investigates the computational complexity of various subcases of the problem.